Recent advances in video broadcasting technology have lead to increased interest in high resolution displays. For example, high-definition television (HDTV) systems have significantly higher resolution than traditional standard definition (SD) broadcast formats such as the National Television System Committee (NTSC) format, the Sequential Color with Memory (SECAM) format, and the Phase Alternating Line (PAL) format. The HDTV format is available in a number of different display resolutions including 1280×720 pixels and 1920×1080 pixels with a large palette of colors.
The increased video resolution in HDTV is of no benefit unless the signals can be successfully transmitted and received by the television. Since high resolution signals require a large amount of data to be transmitted in a short period of time, increased transmission speeds and increased bandwidth requirements are imposed on the broadcasting system. Although a variety of compression technologies can be employed such as MPEG-2 to reduce the overall bandwidth requirements on the broadcast system, the compressed signals must still be transmitted and received with as little distortion as possible.
A typical broadcast system includes a video production and distribution center that multiplexes and transports video signals for reception by a subscriber via a set-top box. In video broadcast systems, a real-time switcher is needed so that local content such as commercials can be inserted into video programming. Line driver circuits are used to transmit the signals at high data rates (e.g., up to 3 Gbps) such as when HDTV signals are transmitted over 75 ohm transmission lines. The line driver circuits can be used in the broadcast system for routing and switching of the video signals, as well as in the distribution of the video signals.